Portable electronic devices such as portable telephones (which include cellular telephones, mobile telephones and other portable telephones), music players, portable computers, personal digital assistants, digital cameras, video camcorders, radio receivers, radio transceivers, navigation devices, combinations of these, and the like are becoming indispensable tools for business and personal affairs. Such devices are referred to herein as “portable devices” or “portable electronic devices”. Portable devices are small and lightweight enough to be carried conveniently by a person. There is increasing demand for portable devices that are very compact, light in weight and yet full-featured.
Most portable electronic devices are powered with electricity from batteries. Primary batteries must be replaced once their energy has been consumed. Although they are convenient, primary batteries can be unacceptably expensive for devices that have high energy requirements. Making and disposing of primary batteries both create waste that could harm the environment.
Secondary batteries can be used multiple times and recharged after each use. However, recharging can be inconvenient. The rate at which batteries can be charged safely is limited. Most recharging technologies require from minutes to hours to recharge a secondary battery. Although better secondary battery technologies are being developed, secondary batteries tend to be heavy and can degrade over time. Frequent fast or partial charging can cause the performance of rechargeable batteries to degrade at an accelerated rate.
Fuel cells convert energy from a fuel, such as hydrogen or methanol, into electricity. Fuel cells are an attractive power source for portable electronic devices, in part because they have the potential to provide higher energy densities than most battery technologies. Thus, a fuel-cell-powered device can potentially offer extended runtime and/or higher power output than a comparable battery-powered device. Another advantage of fuel-cells for powering portable devices is that refueling can be accomplished much more quickly than recharging a storage battery. Fuel cell performance remains relatively constant under a wide range of working conditions.
Several fuel cell technologies being developed for portable applications supply fuel in replaceable fuel cartridges. The fuel cartridges are not refillable by a user. Examples of such cartridge-based technologies include:                Mobion™ from MTI MicroFuel Cells Inc. of Albany N.Y.        The power supplies being developed by Medis Technologies Ltd. of New York, N.Y.        U.S. Pat. No. 6,665,549 discloses a system for replenishing power sources for mobile devices that may include a fuel cartridge dispenser.        U.S. Pat. No. 6,326,097 discloses micro fuel cell power chargers that include disposable fuel ampoules or refillable fuel tanks.        US 2004/0146769 discloses a fuel cell cartridge for portable electronic devices.        US2004/0151962 discloses a fuel cartridge for direct methanol fuel cells.        US2005/0023236 discloses a fuel cartridge with a flexible liner that is connectable to a fuel cell.        US2005/0074643 discloses fuel cartridges for fuel cells.        US2005/0022883 discloses a fuel cartridge with a connecting valve for connecting the fuel cartridge to a fuel cell or to a refilling device.        
A device that requires pre-filled fuel cartridges for operation has many of the same disadvantages as a device that uses primary batteries for power. Multiple cartridges must be purchased and kept on-hand to maintain the operation of the device. The cost of cartridges becomes a major consideration, especially when used in devices that have high power requirements. The cost of a cartridge can be significantly more than the cost of the fuel contained within the cartridge because cartridges must contain the fuel safely and, provide reliable mechanisms to keep the fuel inside the cartridge until it is desired to supply the fuel to a device and connect to supply fuel to the device without leaking fuel. Further, cartridges should be replaced only when the current cartridge is fully spent. A cartridge that is not completely spent will contain waste fuel with economic, environmental and/or safety implications for disposal
Experience with primary batteries suggests that users will find pre-filled cartridges satisfactory only if the time between cartridge replacements is long or the cost of cartridges is extremely low. Achieving either of these objectives is difficult. Designing inexpensive cartridges is difficult because such cartridges must safely contain flammable fuels. Designing cartridges that are long-lasting requires either large volumes or more-expensive fuel storage technologies.
Some fuel-cell-powered devices have on-board fuel reservoirs. The on-board fuel reservoirs can be refilled with fuel. Non-limiting examples of fuels that could be used to power a fuel-cell-powered device are hydrogen; methanol; formic acid; butane; and borohydride compounds. Fuel can be added to an on-board fuel reservoir either through application of a field refueling cartridge or through the use of a fixed fueling station. For example:                US 2005/008908 describes a portable hydrogen storage device that can be used to transfer hydrogen fuel to a portable electronic device such as a laptop computer.        US2005/0155668 describes a refilling system for fuel cells.        US2004/0175599 discloses fuel cell replenishment using a cartridge.        US2004/0072049 discloses a fuel container and delivery apparatus for a liquid-fuel cell system.        US2004/0205032 describes a network of refilling stations for hydrogen-powered vehicles.        U.S. Pat. No. 6,755,225 discloses a transportable hydrogen refilling station for dispensing gaseous hydrogen from high pressure tanks.        US2003/0021743 discloses a fuel cell refueling station and system.        
Providing a portable device having a refillable fuel reservoir does not provide a complete solution to the above problems because of the high cost of fueling stations relative to the portable devices that they service. Even having a home fueling station is not ideal since a portable device may run low on fuel while its user is not at home.
While portable devices powered by fuel have a number of advantages over battery-powered devices, some of which are outlined above, there is a need for cost-effective and convenient ways to replenish the fuel supplies in such devices.